1. Field of the Invention
The present invention relates generally to a shipping container for large cylindrical sleeves, and also to a method for handling a cylindrical sleeve in the fabrication of nonwoven fabrics. More particularly, the subject invention pertains to a shipping container for large cylindrical sleeves which are used, among other purposes, in the production of nonwoven fabrics. In this area of technology, the present invention is useful in shipping a blank cylindrical backing sleeve from its production facility to a surfacing machine, mounting and aligning the blank cylindrical backing sleeve on a mandrel in the surfacing machine, after surfacing, removing the cylindrical backing sleeve from the mandrel in the surfacing machine, transporting the machined cylindrical backing sleeve from the surfacing machine to a nonwoven fabric production facility, and mounting and aligning the machined cylindrical backing sleeve on a nonwoven fabric producing machine.
2. Discussion of the Prior Art
It is known in the prior art to produce relatively large machined cylindrical backing sleeves which are used, among other purposes, in the production of nonwoven fabrics. In general, nonwoven fabrics can be produced by directing controlled water flows against a layer of fibers supported on a cylindrical backing sleeve having a predetermined topography with patterns of pyramids and hole openings formed thereon, as disclosed for instance in Drelich et al. U.S. Pat. No. 5,098,764. The cylindrical backing sleeve disclosed in the '764 patent has a three-dimensional surface which includes a plurality of pyramids disposed in a pattern thereover. The sides of the pyramids are at an angle of greater than 55.degree. to the surface of the cylindrical backing sleeve, and an angle of 75.degree. produces excellent fabrics. The cylindrical backing sleeve also defines a plurality of hole openings therein disposed in the areas where the sides of the pyramids meet the backing sleeve. This prior art approach to producing nonwoven fabrics is disclosed in detail in Drelich et al. U.S. Pat. No. 5,098,764.
The length of the cylindrical backing sleeve as described hereinabove can vary in different embodiments from several feet to thirteen or fourteen feet or more. The pyramids and holes defined on the surface of the cylindrical backing sleeve are quite small, the number of pyramids is typically 100 to 2500 per square inch, and the number of holes may typically be 400 to 5000 per square inch, with the diameter of each hole typically being between 0.010 and 0.035 inches. As disclosed in U.S. Pat. No. 5,098,764, a hole is typically positioned at each corner of each pyramid and at the center of each side of each pyramid.
Such a cylindrical backing sleeve having a surface topography with such fine details can be produced on a surfacing machine in which a cylindrical sleeve blank, typically formed of a suitable plastic material, is mounted for rotation on a mandrel in the surfacing machine. The cylindrical sleeve blank is rotated on the mandrel past a surfacing head operating against the cylindrical sleeve blank. During a surfacing operation, the surfacing head is slowly translated along the length of the cylindrical sleeve blank, and material is selectively removed from the surface of the cylindrical sleeve blank to form a pattern of the type described in U.S. Pat. No. 5,098,764.
Accordingly, with the arrangement as described hereinabove, the surface of a cylindrical backing sleeve is selectively machined to produce a desired very fine pattern of pyramids and holes thereon. The cylindrical backing sleeve might typically have a diameter of 3-6 feet and a length of 4 to 14 feet, and the total surfacing process for a cylindrical sleeve that size might typically take one to three weeks, operating 24 hours a day.
The resultant machined cylindrical backing sleeve must typically be removed from the surfacing machine, and shipped from the surfacing facility to a nonwoven fabric production facility where the cylindrical backing sleeve is used to produce nonwoven fabric in a manner as disclosed in U.S. Pat. No. 5,098,764. Moreover, the surfaced cylindrical backing sleeve defines a very fine pattern of pyramids and holes on its surface which must not be damaged during the transportation process.
The present invention concerns a shipping container which is specifically designed to be useful in shipping a blank cylindrical backing sleeve from its production facility to a surfacing facility, mounting and aligning the blank cylindrical backing sleeve on a mandrel in a surfacing machine, after machining, removing the cylindrical backing sleeve from the mandrel in the surfacing machine, transporting the machined cylindrical backing sleeve from the surfacing facility to a nonwoven fabric production facility, and mounting and aligning the machined cylindrical backing sleeve on a nonwoven fabric producing machine.
At the conclusion of a nonwoven fabric production the shipping container is used to remove the sleeve from the nonwoven fabric producing machine and for storage of the sleeve.